Well, that won't work well unless you've extracted the static files out of the Struts jar.

As the S2 documentation states, the expected filter mapping is "/*". This is because Struts contains static files (the Dojo libraries, in this case), and expects to see *every* request, so it can serve those files.

By mapping to something other than the recommended mapping you're bypassing the default S2 behavior, and must adjust your deployment accordingly.